Cold gas spraying is a coating method by which metal layers, for instance copper, silver, aluminum and the like, can be deposited onto a substrate, for instance a workpiece to be coated.
It is only to a limited extent possible to produce ceramic layers by cold gas spraying, via the deposition of so-called composite layers. In this case, ceramic particles are embedded in larger metal particles and thereby co-deposited onto the substrate. Through suitable heat treatment of the layers deposited in this way, a ceramic layer can be generated by temperature-induced diffusion of the ceramic particles and the metal matrix.
DE 10 2004 059 716 B3 discloses a cold gas spraying method. A carrier gas flow is generated, and particles are introduced into it. The kinetic energy of the particles leads to layer formation on a substrate. The substrate has a structural texture, which is transferred onto the layer being formed.
Using a suitable composition of the particles, a high-temperature superconducting layer can thereby be produced on the substrate. Here again, subsequent heat treatment of the substrate provided with the layer is proposed.
In contrast to the typical thermal or plasma spraying methods such as vacuum plasma spraying (VPS), atmospheric plasma spraying (APS) and high velocity oxy-fuel flame spraying (HVOF), ceramic particles cannot be used directly in the cold gas spraying method since they generally do not adhere to the substrate.